From classic 46/47/48RE to late-model 66RFE, 68RFE, and AS69RC, Monster builds dyno-tested units engineered to conquer Cummins torque and HEMI power—whether you tow, work, or play.
Stock transmissions have known weak points—especially under heavy loads, big tires, or added power. We target those failure modes with stronger hard parts, superior friction materials, recalibrated hydraulics, and matched converters to deliver lasting reliability.
Go-to 4-speed for Magnum 5.2L & 5.9L V8s. We solve governor pressure and overdrive clutch failures for dependable daily driving and towing.
Built for the legendary 5.9L Cummins. Fortified to prevent overdrive burn-up and cross-leaks, ready for diesel torque and heavy work.
The ultimate 4-speed for high-output Cummins. Options for sled pulling, racing, and extreme towing.
Now available for 2012–2018 HEMI 5.7L/6.4L 2500/3500. Addresses known clutch pack heat and valve body wear for longer life with towing and larger tires.
Modern 6-speed for 6.7L Cummins. We correct valve body and clutch drum flaws for dependable service under load and tuning.
2013–2018 chassis-cab/HD 3500/4500/5500 with 6.7L Cummins. Built to thrive in commercial duty with improved lubrication and friction durability.
Use year and engine as a quick guide. HD/chassis-cab models may differ—verify by VIN or transmission tag when possible.
| Transmission | Engine(s) | Typical Model Years | Notes |
|---|---|---|---|
| 46RE | 5.2L / 5.9L Magnum (Gas) | ~1996–2002 | Ram 1500/Van applications |
| 47RE | 5.9L Cummins (Diesel) | ~1996–2002 | Early 2500/3500 |
| 48RE | 5.9L H.O. Cummins (Diesel) | ~2003–2007 | 2500/3500 |
| 66RFE | 5.7L / 6.4L HEMI (Gas) | ~2012–2018 | Primarily 2500/3500 HEMI |
| 68RFE | 6.7L Cummins (Diesel) | ~2007.5–Present | 2500/3500 (most non-chassis-cab) |
| AS69RC | 6.7L Cummins (Diesel) | ~2013–2018 | HD/chassis-cab 3500/4500/5500 |
From our workshop to your driveway, every build is backed by our commitment to quality and performance.
We target known Chrysler weak points with stronger hard parts, superior clutches, and recalibrated hydraulics to ensure durability.
Converters are specced to your engine and use case—from heavy towing single-disc to competition multi-disc.
No transmission ships until it passes our multi-point dyno test. Install with confidence.
Talk to specialists who build and test these units daily. Get the right recommendation first time.
Backed by Monster’s coverage and support for real-world use.
Streamlined logistics and an easy core return process to minimize downtime.
Answers to the most common questions for HEMI and Cummins trucks, including 66RFE, 68RFE, and AS69RC.
If you have a 2012–2018 Ram 2500/3500 with a 5.7L or 6.4L HEMI, you likely have a 66RFE (gas). Most 6.7L Cummins 2500/3500 trucks use the 68RFE. HD/chassis-cab trucks may use the AS69RC—check your VIN or trans tag to confirm.
The AS69RC is a heavy-duty Aisin unit used mainly in 2013–2018 3500/4500/5500 chassis-cab/HD trucks with the 6.7L Cummins. It’s designed for severe commercial service and PTO use. The 68RFE is common in retail 2500/3500 pickups.
For 66RFE/68RFE, upgraded frictions/steels, recalibrated valve body, and a tow-spec converter are key. For AS69RC, we focus on friction durability, hydraulic control, and converter options appropriate for PTO/towing loads.
Yes—tell us your tune, tire size, axle ratio, trailer weight, and usage. We’ll recommend clutch packs, valve body calibration, and converter stall to suit your combo.
For stock or lightly modified trucks used for daily driving or light towing, our Heavy Duty StreetMonster builds are a perfect fit. For trucks with tuners, larger turbos, or those used for heavy hauling, we strongly recommend our Sport/Track series with billet components.
Yes. Many 48RE issues stem from worn valve bodies and failing governor pressure solenoids. Our builds include fully remanufactured and calibrated valve bodies and upgraded electronics to restore crisp, reliable shifting and proper line pressure rise.
A multi-disc (or triple-disc) converter is highly recommended for any Cummins engine making over 400 HP or 800 lb-ft of torque. It provides significantly more clutch surface area to prevent slippage under high load, ensuring all your power makes it to the ground.
Our transmissions are designed as direct, bolt-in replacements for the factory unit. While installation is a job for a confident mechanic with the right tools, no custom modification is required. They arrive ready to install.